There are many types of machine operations which require that a workpiece be accurately and firmly held during operation thereon preferably by means which do not damage or mar the workpiece. The holding means must also be strong enough to prevent twisting and other movements of a workpiece, which movements could be created by torque acting on the workpiece which, if strong enough, might cause undesirable rotation and twisting of the working member and the tool working thereon such as a rotating machine tool, a honing mandrel or similar device. Also, the workpiece holder means must be so constructed as to be able to receive and clamp on the workpiece, preferrably while the workpiece is aligned with the tool. No known device has all of these capabilities and furthermore no known workpiece gripping and holding device is able to automatically receive workpieces fed thereto such as by means of a loading and feeding device such as disclosed in copending Sunnen et al U.S. patent application Ser. No. 098,549, filed Sept. 21, 1987.
Furthermore, known prior art gripping and holding devices are unable to be adjusted to accommodate workpieces of different sizes, and in some cases, shapes and to grip them in a manner which does not damage them or mar their surfaces, and known devices are relatively complicated and are vulnerable to excessive torque conditions which can produce damage to the workpieces and to the tool and can produce inaccuracies in the surfaces being worked on such as surfaces being honed as by twisting or bending of the working member or the tool or both when the workpiece is under load. Robotic devices likewise do not solve these problems.